JP6732885B2 - Light emitting crystal and its manufacture - Google Patents

Description

The present invention relates to the field of light emitting crystals (LCs), and more particularly quantum dots (QDs). The present invention provides methods of making such luminescent crystals in compositions containing luminescent crystals, and in electronic devices, decorative coatings, and intermediates including LC.

Light emitting crystals, specifically quantum dots, are a well-known class of materials. Such QDs have many applications in electronic and industrial and commercial products such as light emitting diodes or displays.

Loredana Prodesescu et al. (Nano Lett., 2015, Volume 15, pp 3692-3696) disclose a new class of high quality luminescent quantum dots (QDs). QDs were synthesized with very high dimensional accuracy using inexpensive chemistries; QD diameters were controlled by adjusting synthesis parameters such as temperature and reaction time. However, the method was difficult to control (due to the very high particle growth rate of the composition of this material) and difficult to scale up, so only very small amounts were synthesized. Furthermore, the reaction is non-stoichiometric, leading to large amounts of by-products. Furthermore, the reaction can only be carried out in high boiling solvents such as octadecene (because of the high reaction temperature), which means that QD can be reduced in low boiling solvents such as toluene for end use applications. If necessary, solvent exchange is required. This synthetic route is known as the "hot injection method" using standard laboratory equipment. Because of these disadvantages, methods of synthesizing QDs are not commercially attractive and make QDs expensive.

Pfenninger et al. (WO 2007/109734) discloses similar materials, but obtained in the form of thin films by vacuum deposition. Such a manufacturing method is also considered to be disadvantageous.

Guo et al. (WO 2014/007966) disclose a standard luminescent QD of the core-shell type based on CdSe or InP, which further comprises C5-C8 carboxylic acids. Standard CdSe and InP require a larger bandgap semiconductor shell (eg ZnS) to achieve the desired optical functionality. This additional synthetic step further increases their cost and is a disadvantage for many applications.

Dandang Zhang et al. (JACS, 2015, pages 9230-33) disclose liquid phase synthesis of cesium lead perovskite nanowires. Like Prodesescu, supra, the literature discloses obtaining nanowires by the hot injection method using standard laboratory equipment. Such nanowires are not quantum dots.

Kojima Yohiro et al. (JP-A-2014-078392) discloses an electroluminescent device containing a perovskite compound. Perovskites are obtained by a specific solution process called melt-dissolving. This is a bottom-up method that includes the step of crystallizing the target compound. Such processing is difficult to scale up and difficult to control.

The object of the present invention is therefore to mitigate at least some of these disadvantages of the state of the art. In particular, it is an object of the invention to provide an improved method of manufacturing LC/QD. A further object is to provide new materials, including LC/QDs, which are suitable for a wide variety of applications such as electronics and light devices, and decorative coatings.

These objects are achieved by the method according to claim 1, the ink according to claim 9, the intermediate product according to claim 17, and the use according to claim. Further aspects of the invention are disclosed in the description and the independent claims, and preferred embodiments are disclosed in the description and the dependent claims. The invention is particularly directed to:
Method for producing light emitting crystal, specifically quantum dot (first aspect);
Compositions in the form of suspensions, also called "inks" or "prepolymer dispersions", and their use (second aspect);
Solid polymer composition and its use (third aspect);
Intermediate product (fourth aspect);
Devices such as electronic devices, optical devices, and articles including coated surfaces (fifth aspect);
Method for producing polymer composition (sixth aspect);
Manufacturing method of intermediate product (seventh aspect); and manufacturing method of device (eighth aspect)
I will provide a.

The present invention is described in detail below. It should be understood that the various embodiments, choices, and ranges provided/disclosed herein may be freely combined. Furthermore, selected definitions, embodiments, or ranges may not apply in some particular embodiments.

Unless otherwise stated, the following definitions apply herein.

The terms "a", "an", "the", and like terms used in the context of the present invention, unless otherwise indicated herein or clearly contradicted by context, refer to singular and plural forms. Both are included. Furthermore, the terms "including," "containing," and "comprising" are used herein in their open, non-limiting sense. The term “containing” includes both “comprising” and “consisting of”.

Unless otherwise indicated herein, or unless clearly contradicted by context, percentages are by weight.

The term "luminescent crystal" (LC) is known in the art and means a 2-50 nm nanocrystal made of semiconductor material. The term includes quantum dots, which are typically nanocrystals in the range 3-15 nm, up to 50 nm. Preferably, the luminescent crystal is approximately equiaxed (eg sphere or cubic). A particle is considered to be substantially equiaxial if all aspect ratios (long axis direction: short axis direction) in the three orthogonal dimensions are 1-2.

LC, as the term indicates, exhibits luminescence. In the context of this invention, luminescent crystals are typically single crystal particles that are spatially separated from other particles by the presence of surfactants. It exhibits a direct bandgap (typically in the range 1.1-3.8 eV, more typically 1.4-3.5 eV, even more typically 1.7-3.2 eV). , Is a semiconductor material. In response to illumination with electromagnetic radiation equal to or higher than the band gap, valence band electrons are excited into the conduction band, leaving electron holes in the valence band. The shaped excitons (electron-electron hole pairs) are then radiated radiatively in the form of photoluminescence, showing a photoluminescence quantum yield of at least 1% at the maximum intensity centered around the LC bandgap value. Rejoin. In contact with external electron and electron hole sources, the LC can exhibit electroluminescence. In the context of the present invention, LC exhibits no mechanical luminescence (eg piezoluminescence), chemiluminescence, electrochemiluminescence or thermoluminescence.

The term "quantum dot" (QD) is known and means in particular semiconductor nanocrystals, which typically have a diameter of 3 to 15 nm. In this range, the physical diameter of the QD is smaller than the bulk excitation Bohr radius, predominantly the quantum confinement effect. As a result, the electronic state of the QD, and thus the bandgap, is a function of the QD composition and physical diameter, ie the absorption/emission color is related to the QD diameter. The optical quality of QD samples is directly related to their homogeneity (more monodisperse QDs have a smaller FWHM of emission). When the QD reaches a diameter larger than the Bohr radius, the quantum confinement effect is hindered and the non-radiative path for exciton recombination can become dominant, so the sample may no longer be luminescent. Therefore, QDs are a particular subgroup of nanocrystals, defined in particular by their size and size distribution. The properties of QDs are directly related to these parameters, distinguishing them from nanocrystals.

The term "solvent" is known in the art and includes in particular aliphatic hydrocarbons, aromatic hydrocarbons, ethers (such as glycol-ethers), esters, alcohols, ketones. The above organics may be substituted by one or more substituents, eg halogen (eg fluoro), hydroxy, C1-4alkoxy (eg methoxy or ethoxy), and alkyl (eg methyl, ethyl, isopropyl). Or may not be substituted. The above organic substances include linear, branched, and cyclic derivatives. There may be an unsaturated bond in the molecule. The compounds typically have 4 to 24 solid carbon atoms, preferably 5 to 12 solid carbon atoms, and most preferably 6 to 10 solid carbon atoms.

The terms "surfactant," "ligand," "dispersant," and "dispersing agent" are known in the art and have essentially the same meaning. In the context of the present invention, these terms mean organic substances other than solvents which are used in suspensions or colloids to improve the separation of particles and prevent agglomeration or precipitation. Without being limited to theory, it is believed that the surfactant physically or chemically attaches to the particle surface before or after the particles are added to the solvent, thereby providing the desired effect. The term "surfactant" includes polymeric materials and small molecules; surfactants typically include polar functional end groups, and non-polar end groups. In the context of the present invention, the solvent (eg toluene) is not considered a surfactant.

The term suspension is known and means a heterogeneous fluid with an internal phase (i.p.) that is a solid and an external phase (e.p.) that is a liquid. The outer phase comprises one or more dispersants/surfactants, optionally one or more solvents, and optionally one or more prepolymers.

The term "polymer" is known and includes organic and inorganic synthetic materials. The term "prepolymer" includes both monomers and oligomers.

The term “solution processing” is known in the art and means the application of coatings or thin films to substrates using solution-based (=liquid) starting materials. In the context of the present invention, solution processing relates to the manufacture of goods, for example electronics, light devices, and articles comprising (decorative) coatings, and intermediate products comprising QD composites or QD layers. Typically, application of one or more suspensions is done at ambient conditions.

The term “QD composite” means a solid inorganic/organic composite material that includes LC/QD, a surfactant, and a matrix. Forms of QD composites include films, fibers, and bulk materials. Since LC/QDs are not electronically addressed, QD composites are used in applications where LC/QDs perform only optical functions.

In a QD composite, the LC/QDs are incorporated into a matrix, such as a polymer matrix or an inorganic matrix, to spatially separate the LC/QDs from each other. Depending on the application, the thickness of the QD composite film can vary over a wide range, but is typically 1 to 1000 microns.

The term "QD layer" means a thin layer comprising luminescent crystals (specifically QD) and a surfactant and is free or essentially free of further components such as a matrix/binder. The QD layer may find various applications such as quantum dot light emitting diodes (QLEDs), or quantum dot solar cells. In these applications, the LC/QDs are electronically addressed; by applying a voltage, current flows through the QD layer. Depending on the application, the thickness of the QD layer can vary over a wide range, but is typically 3-200 nm, preferably 5-100 nm, most preferably 6-30 nm. The QD layer can be composed of an LC/QD monolayer and thus has a thickness equal to the size of the LC/QD used, thus defining a lower limit for the thickness.

The invention will be better understood with reference to the figures.

FIG. 1a outlines various aspects of the invention. FIG. 1b outlines various aspects of the invention. In FIG. 1b, the x-axis shows the particle size and the y-axis shows the number of particles. FIG. 2 shows a TEM image of a typical QD synthesized according to the present invention, showing the cubic nature of the crystal structure. FIG. 3 shows a SEM image of a typical starting solid material powder prepared by precipitation.

In a first aspect, the invention relates to a method for producing a luminescent crystal, in particular a luminescent crystal from a class of quantum dots. More specifically, the present invention relates to a method for producing a luminescent crystal having a diameter of 2 to 50 nm, preferably 3 to 15 nm, said luminescent crystal being selected from the compounds of formula (I),
M ¹ _a M ² _b X _c (I)
In the formula:
M ¹ represents one or more alkali metals selected from Cs, Rb, K, Na and Li,
M ² represents one or more metals selected from the group consisting of Ge, Sn, Pb, Sb, and Bi,
X represents one or more anions selected from the group consisting of chloride, bromide, iodide, cyanide, thiocyanate, isothiocyanate, and sulfide, preferably selected from the group consisting of Cl, Br, and I. Represents one or more halides,
a represents 1 to 4,
b represents 1-2,
c represents 3 to 9;
The method comprises a step (a) of providing a solid material as defined below, and a step (b) of dispersing the material in the presence of a liquid as defined below.

Hereinafter, embodiments of the present invention will be described in more detail.

LC/QD is known to be an environmentally sensitive material. First, they tend to aggregate, which induces non-radiative recombination pathways, leading to reduced luminescence quantum yields. Therefore, once synthesized, means must be taken to stabilize the LC/QD. The method described herein meets this need by disclosing an improved manufacturing method that provides LC/QD in the form of a stable suspension (“ink”).

The method described herein is considered a "top-down" approach, as the material is first synthesized conventionally and then reduced in size and stabilized to obtain the LC/QD. Good. This method is the opposite of what is known and described in Kovalenko (supra), which is a "bottom-up" approach. The method of the invention is further illustrated, but is not limited by the experiments provided below.

The methods described herein provide LC/QDs with excellent properties. First, small FWHM values (width of emission peak; eg 19 nm for emission at 507 nm) are observed. Second, a high luminescence quantum yield is observed (eg 71% for emission at 507 nm). Therefore, the LC/QD provided by the method of the invention is suitable for many applications in electronics and optical devices. Furthermore, the LC/QD provided by the method of the present invention is also suitable for coated (non-electronic/non-optical) articles such as decorative coatings.

The inventive method is superior to known manufacturing methods. First, it is much more robust and can be easily upscaled. Second, less starting material is required and less by-products are produced. Third, since the synthesis can be carried out directly in a low boiling point solvent, there is no need for solvent exchange to a low boiling point solvent (eg toluene) after LC/QD synthesis. As a result, manufacturing costs are significantly reduced, making LC/QDs available for many applications.

Light-Emitting Crystals/Quantum Dots of Formula (I): The method of the present invention provides LC/QDs with an average diameter of 2 to 50 nm, especially 3 to 15 nm. The LC/QD also has a narrow size distribution, as indicated by the low FWHM value of the emission peak.

In one embodiment, the invention relates to LC/QD of formula (I), wherein a=1, b=1, c=3.

In one embodiment, the invention relates to LC/QD of formula (I), wherein M ¹ =Cs.

In one embodiment, the invention relates to LC/QD of formula (I), wherein M ² =Pb.

In one embodiment, the invention relates to the LC/QD of formula (I), wherein X is a combination of at least two elements selected from the group Cl, Br, I.

In one embodiment, the invention relates to an LC/QD of formula (I) selected from Cs ₁ Pb ₁ X ₃ , especially CsPbBr ₃ , CsPbBr ₂ I. This embodiment includes a corresponding molar mixture of CsBr and PbBr _2, or a mixture of CsI and PbBr _2.

In one further embodiment, the present invention further comprises a doped material, ie where part of M ¹ is replaced by another alkaline metal, or part of M ² is replaced by another. It relates to an LC/QD of formula (I), which is replaced by a transition metal or rare earth element, or a part of X is replaced by another halide.

In one further embodiment, the invention relates to the LC/QD of formula (I) selected from M ¹ SnX ₃ , M ¹ ₃ Bi ₂ X ₉ , M ¹ GeX ₃ .

Compounds of formula (I) include stoichiometric and non-stoichiometric compounds. The compounds of formula (I) are stoichiometric, b and c represent natural numbers; they are non-stoichiometric and b and c represent integers. In one further embodiment, the invention provides a compound of formula (I) wherein some of X is replaced with one or more anions selected from the group consisting of cyanide, thiocyanate, isothiocyanate, and sulfide. ) LC/QD. An exemplary embodiment is
M ¹ _a M ² _b X ¹ _c′ X ² _c″ (I-1)
In the formula:
M ¹ , M ² , a and b are as defined above;
X ¹ represents a specified halide;
X ² represents an anion selected from cyanide, thiocyanate, isothiocyanate, and sulfide;
c′+c″ represents a real number of 3 to 9, and c′/c″ is larger than 0.9.
Since sulfide is 2-, it is counted twice when calculating c″.

Exemplary embodiments of formula (I-1) include CsPbCl _2.9 CN _0.1 , CsSnBr ₂ (SCN) ₁ , Cs ₃ Bi ₂ Br _8.8 (NCS) _0.2 , and CsPbBr _{0. 43} I _2.43 S _0.07 .

Solid material: Suitable solid materials provided in step (a) have a mean particle size of at least 15 nm and a polydisperse size distribution, typically 15 nm to 100 μm, more typically 50 nm to 50 μm. The particle size of the solid material is determined by SEM, TEM, or BET.

Moreover, such solid materials have a chemical composition that corresponds to the desired LC/QD chemical composition. Thus, such a solid material has a stoichiometric composition of a mole of M ¹ , b mole of M ² , and c mole of X.

Such materials may be provided to the method of the invention by different methods of (a1), (a2), (a3), for example as outlined below. The material may be provided to step (b) continuously or discontinuously by known methods.

Wet synthesis process (a1): The production of solid materials according to formula (I) is known per se. The most common methods include wet synthesis processes, for example precipitation processes from solvent-based or aqueous phases. The material may be provided to step (b) continuously or discontinuously by known methods.

This method may be considered "top-down": polydisperse particles in which the solid starting material obtained by wet synthesis has an average particle size (measured by BET, SEM, or TEM) greater than 15 nm. In contrast to the size distribution, the synthesized luminescent crystals show a very narrow size distribution with an average size of 2 to 50 nm (see FIG. 1b). By following the method described herein, the average particle size and polydispersity of the starting materials are reduced to obtain a narrow size distribution and a particle size of 2-50 nm.

Gas phase dry synthesis treatment (a2-1): As an alternative method for producing a solid material according to formula (I), a dry synthesis treatment in the gas phase, in particular decomposition and pyrolysis treatments, for example flame spray pyrolysis Processing. The solid material obtained by this treatment is typically smaller than (a1).

This method may be considered "top down": polydisperse particles in which the solid starting material obtained by dry synthesis has an average particle size of greater than 15 nm (measured by BET, SEM or TEM). In contrast to the size distribution, the synthesized luminescent crystals show a very narrow size distribution with an average size of 2 to 50 nm (see FIG. 1b). Therefore, at least some of the starting material is reduced in size.

Dry Synthesis Treatment by Milling (a2-2): A further method of producing the solid material according to formula (I) is dry milling of the precursor material. In this embodiment, the solid material is a mixture of two or more dry precursors having the formulas aM ¹ ₁ X ₁ and M ² _b X _(c-a) , where the substituents are as defined above. Is. For example, CsPbBr ₃ , Cs ₄ PbBr ₆ is available with the corresponding molar mixture of precursors CsI and PbBr ₂ , or CsPbBr ₂ I is available with the corresponding mixture of precursors CsBr and PbBr ₂ . Then a dry milling treatment, for example using a pestle and a mortar or with a stirred milling ball, gives a dry crystalline material according to formula (I). This treatment can be regarded as a milling-induced solid state reaction.

In-situ formation (a3): Further alternatives for solid materials according to formula (I) include in-situ formation, eg solid state reaction during dispersion treatment. In this embodiment, the solid material is a mixture of two or more dry precursors having the formulas aM ¹ ₁ X ₁ and M ² _b X _(c-a) , where the substituents are as defined above. Is. For example, CsPbBr ₃ , Cs ₄ PbBr ₆ is available with the corresponding molar mixture of precursors CsI and PbBr ₂ , or CsPbBr ₂ I is available with the corresponding mixture of precursors CsBr and PbBr ₂ . The reaction of the two precursors of the solid material then forms the crystalline material according to formula (I) during the dispersion process (ie in situ).

The above precursor can be obtained by a known method, for example, a wet synthesis treatment or a dry synthesis treatment. The person skilled in the art is in the position to select suitable precursors for obtaining the luminescent crystals of formula (I).
Also, since the precursors used are larger than the LC/QDs obtained, this method may be considered "top down".

In one embodiment, the average particle size of the solid material (determined by BET, SEM, or TEM) is at least 15 nm, preferably 15 nm-100 μm, more preferably 50 nm-50 μm.

In an advantageous embodiment, the solid material consists of a single composition having the same stoichiometry as the final LC/QD of formula (I).

Step (b): Without being limited to theory, it is believed that dispersing the starting material in the liquid phase will result in many effects simultaneously or sequentially.

First, the solid material is evenly distributed in the liquid phase.

Second, the solid material comes into contact with the surfactant. It is believed that this coats the material and stabilizes it in the liquid phase.

Third, the particle size of the solid material is reduced. Without being limited to theory, two mechanisms occur: (1) mechanical fragmentation/splitting of particles larger than the final LC/QD size, (2) Ostwald ripening and sintering of particles smaller than the final LC/QD size. It is believed that a monodisperse particle size distribution can be obtained.

In certain embodiments, the average particle size of the solid starting material is at least 1.5 times (preferably at least 2 times, most preferably at least 5 times) the average particle size of the correspondingly synthesized LC/QD. ..

Liquid: As outlined above, the dispersion of step (b) is carried out in the liquid phase. Suitable liquids include (i) liquid surfactants, (ii) combinations of (liquid or solid) surfactants and solvents, (iii) (liquid or solid) surfactants, solvents and (liquid or solids). ) Prepolymers or combinations with polymers, and (iv) (liquid or solid) surfactants with liquid prepolymers.

In embodiment (i), the liquid phase consists (or consists essentially) of a liquid surfactant. This embodiment is advantageous because it is a simple system without solvent.

In embodiment (ii), the liquid phase consists (or consists essentially) of a (liquid or solid) surfactant and solvent combination. This embodiment is advantageous as it allows the use of solid surfactants.

In embodiment (iii), the liquid phase consists (or consists essentially) of a (liquid or solid) surfactant, one or more solvents and a (liquid or solid) prepolymer or polymer. .. This embodiment is advantageous as it provides a composition which may be used directly to prepare an intermediate as defined below.

In embodiment (iv), the liquid phase consists (or consists essentially) of a liquid prepolymer. This embodiment is advantageous as it provides a composition that is solvent-free and may be used directly to make intermediates as defined below.

Solvent: The term solvent has been defined above. For the avoidance of doubt, the term solvent does not include surfactants or prepolymers.

Advantageously, the solvent is selected from the group of hydrocarbons (including straight chain, branched chain and cyclic hydrocarbons), aromatic hydrocarbons, ethers (including glycol ethers), esters, alcohols, ketones. Preferably, the solvent is selected from the group of straight chain and branched chain _C5-24 alkanes, said alkanes being unsubstituted or substituted by phenyl or naphthyl. Most preferably, the solvent is selected from the group of straight chain _C5-15 alkanes and toluene.

In a further embodiment, the solvent exhibits a boiling point below 140°C, preferably below 120°C. As a beneficial aspect of the method of the invention, it is possible to obtain LC/QD at much lower temperatures compared to previous methods such as Protesescu or Zhang described above (both using the synthetic method of 140-200° C.). It is possible.

Prepolymer: The term prepolymer has been defined above. Advantageously, the prepolymer is selected from the group of acrylates, carbonates, sulfones, epoxies, vinyls, urethanes, imides, esters, furans, melamines, styrenes and silicones. Preferably, the prepolymer is selected from the group of acrylates, urethanes, styrenes. Particularly preferably, the prepolymer is selected from the group of acrylates.

Surfactants: A wide variety of surfactants may be used in the context of the present invention. Suitable surfactants may be determined by repeated experiments; the choice depends mainly on the polymer used in the next step, and the nature of the solid material. The surfactant may be selected from the class of nonionic surfactants, cationic surfactants, zwitterionic surfactants, and anionic surfactants. It is known in the art to combine two or more surfactants to improve the positive properties; combinations of such surfactants are also a subject of the present invention.

Nonionic surfactants include: maleic acid polymers such as poly(maleic anhydride-ortho-1-octadecene), polyamines, alkylamines (eg N-alkyl-1,3-propylene-diamine, N- Alkyldipropylene-triamine, N-alkyltripropylene-tetraamine, N-alkylpolypropylene-polyamine), poly-(ethyleneimine), polyester, alkyl ester (eg cetyl palmitic acid), alkyl polyglycol ether (eg 3-25). Aliphatic alcohol polyglycol ethers having ethoxy units (EO), such as Dehypon E124), and oxo alcohol polyglycol ethers), mixed alkyl/aryl polyglycol ethers, alkyl polyglucosides (APG), aliphatic alcohols, for example: Mention may be made of stearyl alcohol (eg Lorol C18™).

Examples of the nonionic surfactant further include polymer ethoxylate and/or propoxylate (EO/PO) adduct surfactants such as aliphatic alcohol alkoxylates and alcohol EO/PO adducts (aliphatic alcohol EO/ PO adducts, including oxo alcohol EO/PO adducts), EO/PO block copolymers, ethylenediamine ethylene oxide-propylene oxide (EO/PO) block copolymers, end-capped (aliphatic) alcohol EO adducts and EO/PO adducts (Eg butyl end caps), esters of carboxylic acids, especially EO/PO adducts and sorbitan esters (eg from the group of SPAN).

Nonionic surfactants further include alkoxysilanes and their hydrolysis products.

Nonionic surfactants further include alkylphosphines, alkylphosphines oxides (eg, trioctylphosphine oxide-TOPO), and alkylthiols.

Examples of the nonionic surfactant further include alkyl esters of fatty acids (for example, cetyl palmitic acid, lauric acid, capric acid).

A preferred class of nonionic surfactants are alkylimines, alkylamines such as dioctylamine, oleylamine, octadecylamine, hexadecylamine.

Cationic surfactants include: Alkylammonium halides, more specifically alkyltrimethylammonium halides, such as cetyltrimethylammonium bromide, dialkyldimethylammonium halides, such as distearyldimethylammonium chloride, trialkylmethylammonium halides. , For example, trioctylmethylammonium chloride, diquarternary polydimethylsiloxane.

Zwitterionic surfactants include: betaines such as caprylic acid glycinate, cocoamidopropyl betaine, and cocoamphodiacetic acid disodium.

Anionic surfactants include sulfates, sulfonates, phosphates, and carboxylates. Specific examples include phosphoric acid esters of alkyl ethers, ammonium lauryl sulfate, alkali lauryl sulfate, and related alkyl ether sulfates such as alkali laureth sulfate.

A preferred class of anionic surfactants are the carboxylates of the class of fatty acids such as oleic acid, stearic acid, palmitic acid.

In a preferred embodiment, the surfactant is selected from the following list: SP 13300, SP 20000, SP 24000SC, SP 41000, SP540, BYK9077, Hypermer KD1-SO-(AP), Span65, Span80, Span85, Methoxy. -Ethoxy-ethoxy-acetic acid, oleylamine, oleic acid, stearic acid, poly(maleic anhydride-ortho-1-octadecene), and TOPO.

In a more preferred embodiment, the surfactant is selected from the following list: SP 13300, SP 20000, SP 24000SC, SP 41000, SP540, BYK9077, Hypermer KD1-SO-(AP), Span65, Span80, Span85, Methoxy-ethoxy-ethoxy-acetic acid, stearic acid, poly(maleic anhydride-ortho-1-octadecene), and TOPO, hexadecylamine, octadecylamine, dioctylamine.

In a further embodiment, the surfactant is a non-polar selected from the group of alkyl or alkyl-ether chains having 4 to 30, preferably 6 to 24, most preferably 8 to 20 carbon atoms. It is selected from the group of anionic surfactants, cationic surfactants, nonionic surfactants, and zwitterionic surfactants, which contain end groups.

In a further embodiment, the surfactant has the formula _{RO- (C 2 H 4 O)} m (C 3 H 6 O) n - ( wherein, m and n is from 0 to 10 independently, m+n>2, R is C _1-5 -alkyl) having one or more chemical moieties selected from the group of alkyl ethers having C _1-5 -alkyl, anionic surfactants, cationic surfactants, non- It is selected from the group of ionic surfactants and zwitterionic surfactants.

In a further embodiment, the anionic surfactant has the formula (II):
_{R (OC n H 2n) q} OCH 2 C (O) OH (II)
Wherein R is C _1-5 -alkyl, q is an integer from 0 to 5, and n is an integer from 1 to 3. .. Five particularly preferred compounds of that class are:
And in the formula, q is 0 to 4. This corresponds to a compound of formula (II) in which R is methyl, n is 2 and q is an integer from 0-4. Particularly preferred compounds of that class are:
Is.

Dispersion treatment: Suitable dispersion treatments include dispersion methods involving milling balls. In a preferred embodiment, the dispersion method is ball milling, preferably using a stirred ball mill. In a preferred embodiment, the ball diameter is less than 5 mm, preferably less than 500 microns. In a further embodiment, the dispersion method is ball milling with a ball diameter of 10-1000 μm, preferably 20-500 μm. In a further embodiment, the dispersing method is ball milling with such a specific power input per unit mass of suspension of at least 10 W/kg, preferably 100 W/kg, most preferably 1000 W/kg. In one further embodiment, the temperature of the suspension during the dispersing process is below 140°C, preferably below 120°C, most preferably below 70°C. Surprisingly, the use of agitated milling balls converts a solid material as defined above into an LC/QD with excellent optical properties (high quantum yield, small FWHM), and excellent properties. , And LC/QD with low reaction temperature can be provided. This is believed to be a significant advantage over known methods.

In a further embodiment of the method of the present invention, the solid material:liquid material mass ratio (solvent+prepolymer+surfactant) is from 0.0001 to 0.5, preferably from 0.0005 to 0.1, most preferably. Is in the range of 0.001 to 0.05.

In a further embodiment of the method of the present invention, the surfactant:solids material weight ratio ranges from 100 to 0.1, preferably from 50 to 0.5, most preferably from 20 to 1.

Work-up: In a further embodiment, the as-synthesized LC/QD, for example as outlined in steps (b-2), (b-3), (b-4) and (b-5) below. Post-treatment may be performed.

In one embodiment of such work-up, the halogen atom X of the synthesized LC/QD can be completely or partially replaced with another halogen atom by anion exchange. For anion exchange (b-2), in particular alkali halides such as NaI, KI, LiI and lead halides such as PbI ₂ may be used. This allows fine tuning of the emission peak.

In a further embodiment of such post-treatment, two or more types of luminescent crystals of formula (I) are mixed. The emission peak of the composition is adjusted by mixing different types of luminescent crystals, ie by combining two suspensions of such luminescent crystals. (B-5)

In a further embodiment, the compositions of the invention may be purified from excess surfactant by diafiltration of the synthesized composition. (B-3)

In a further embodiment, the LC/QD solids of the composition of the invention may be increased by diafiltration or solvent evaporation of the synthesized composition. (B-4)

In a second aspect, the invention relates to the composition in the form of a suspension, also called "ink", and its use. Hereinafter, embodiments of the present invention will be described in more detail.

Accordingly, the invention provides (i) a luminescent crystal of formula (I) as described herein; (ii) as described herein, but with oleylamine, oleic acid, and trioctylphosphine. A surfactant other than;; (iii) any solvent as described herein; and (iv) any polymer or prepolymer as described herein. The composition is provided in the form of a suspension. Such compositions are new and may be obtained by the process of the invention as described in the first aspect of the invention.

In one embodiment, the invention provides a suspension whose quantum yield is higher than 20%, preferably higher than 50%, most preferably higher than 70%.

In a further embodiment, the invention provides a suspension in which the FWHM of the LC/QD for visible emission is less than 50 nm, preferably less than 40 nm, most preferably less than 30 nm.

In a further embodiment, the invention provides a suspension wherein the LC/QD FWHM having an emission peak between 480 and 550 nm or between 600 and 680 nm is less than 40 nm, preferably less than 30 nm, most preferably less than 20 nm. provide.

In a further embodiment, the invention provides a suspension wherein the LC/QD FWHM having an emission peak between 480 and 530 nm is less than 40 nm, preferably less than 30 nm and most preferably less than 20 nm.

The amounts of components (i), (ii), (iii) and (iv) can vary over a wide range and depend, inter alia, on their intended use and the nature of the surfactant.

In one embodiment, the mass ratio of luminescent crystals (i):liquid material (ii)+(iii)+(iv) is 0.0001-0.5, preferably 0.0005-0.3, most preferably 0. The range is 0.001 to 0.1.

In one further embodiment, the mass ratio of surfactant (ii): luminescent crystal (i) is in the range 100-0.05, preferably 50-0.2, most preferably 20-1.

In one further embodiment, the concentration of the polymer or prepolymer ranges from 0.1 to 30% by weight of the total composition, preferably 0.5 to 20% by weight, most preferably 1 to 10% by weight. is there.

As outlined above, components (i) and (ii) are essential, while components (iii) and (iv) are optional. Accordingly, the present invention relates to an ink comprising (ie, comprising or consisting of):
Comprising components (i) and (ii), (ii) being a liquid and not (iii) and (iv);
Includes components (i), (ii), (iii) and not (iv);
Contains components (i), (ii), (iv) and not (iii);
Includes components (i), (ii), (iii), and (iv).

In one further embodiment, the composition comprises components (i), (ii), (iii) and (iv), component (ii) comprising an aromatic hydrocarbon, preferably toluene. Component (iv) comprises a cyclic olefin copolymer.

In one further embodiment, the composition comprises components (i), (ii), (iii) and (iv), component (ii) comprising straight chain alkanes and/or aromatic hydrocarbons, Component (iv) comprises a styrene copolymer and/or a styrene block copolymer.

Solvent-free ink: The present invention comprises components (i), (ii) and (iv) in the form of a suspension as described herein, but without solvent (iii), or in essence. A composition that is essentially free. In this embodiment, the LC/QD(i):liquid material (prepolymer (iv)+surfactant (ii)) mass ratio is preferably 0.0001-0.5, preferably 0.0005-0. .3, most preferably 0.001 to 0.1. Such compositions are sometimes referred to as solvent-free inks and are particularly suitable for supplying intermediate or device manufacturers as described below.

Prepolymers particularly suitable for solventless inks include acrylates, epoxies, urethanes, silicones, styrenes. Again, the term prepolymer includes monomers and their oligomers. Preferably, the solventless ink comprises acrylate.

An ink is considered solvent-free if it contains less than 10% by weight of solvent, preferably less than 1% by weight.

In a further embodiment, the solventless ink further comprises a polymerization initiator, such as a radical photopolymerization initiator, or a temperature sensitive radical initiator.

Concentrate: The present invention is free of or essentially free of solvent (iii), free or essentially free of prepolymer (iv), wherein surfactant (ii) is a liquid surfactant. Certain compositions are provided in the form of suspensions as described herein. In this embodiment, the mass ratio of surfactant (ii):LC/QD(i) is preferably in the range 100 to 1, preferably 50 to 2, most preferably 20 to 10.

The inks described herein have many applications, and are particularly useful for converting blue light to white light, especially with light emitting diodes (LEDs).

In a third aspect, the present invention relates to solid polymer compositions and uses thereof. The term solid polymer composition means an organic or inorganic polymer matrix comprising LC/QD as described herein. Hereinafter, embodiments of the present invention will be described in more detail.

In one embodiment, the invention provides (i) an LC/QD as described herein and (ii) as described herein, but with oleylamine, oleic acid, and trioctylphosphine. There is provided a solid polymer composition comprising a scavenging surfactant and (iii) a curing/solidifying polymer, preferably selected from organic polymers.

In a further embodiment, the organic polymer is preferably selected from the group of acrylate polymers, carbonate polymers, sulfone polymers, epoxy polymers, vinyl polymers, urethane polymers, imide polymers, ester polymers, furan polymers, melamine polymers, styrene polymers, and silicone polymers. Is selected. Therefore, the polymer preferably comprises repeat units of the prepolymers described herein. Further, the polymer can be linear or crosslinked.

In a further embodiment, the organic polymer is preferably selected from the group of acrylate polymers, epoxy polymers, urethane polymers, styrene polymers, silicone polymers and cyclic olefin copolymers. Therefore, the polymer preferably comprises repeat units of the prepolymers described herein. Further, the polymer can be linear or crosslinked.

In one embodiment, the organic polymer comprises a styrene copolymer and/or a styrene block copolymer, preferably a styrene and isoprene block copolymer, a styrene, ethylene, and butene block copolymer.

In one embodiment, the mass ratio of LC/QD:matrix (polymer+surfactant) in the solid polymer composition is 0.0001-0.1, preferably 0.0005-0.05, most preferably 0. The range is 0.001 to 0.02.

In one embodiment, the surfactant:LC/QD weight ratio in the solid polymer composition is in the range of 100-0.05, preferably 50-0.2, most preferably 20-1.

In a further embodiment, the quantum yield of the solid polymer composition of the present invention is higher than 20%, preferably higher than 50%, most preferably higher than 70%.

In a further embodiment, the FWHM of the inventive solid polymer composition for visible emission is less than 50 nm, preferably less than 40 nm, most preferably less than 30 nm.

In a fourth aspect, the present invention is an intermediate product comprising a sheet-shaped substrate coated with one or more layers, wherein at least one of the layers is a functional layer, and the functional layer is the present specification. An intermediate product comprising the solid polymer composition described in the publication. Hereinafter, embodiments of the present invention will be described in more detail.

In an advantageous embodiment, the functional layer converts blue light into white light. The invention therefore provides the use of the solid polymer composition for converting blue light into white light, especially with light emitting diodes (LEDs) or in liquid crystal displays.

In a fifth aspect, the invention relates to a novel device/article. Hereinafter, embodiments of the present invention will be described in more detail.

In one embodiment, the invention provides an apparatus selected from the group of electronics and optical devices, wherein the apparatus comprises a substrate and a functional layer; said functional layer being herein An LC/QD of formula (I) as described and a surfactant as described herein but excluding oleylamine, oleic acid, and trioctylphosphine. Such a device may be selected from the group consisting of a display, a mobile device, a light emitting device, and a solar cell, in particular the device is a liquid crystal display or a quantum dot LED (QLED).

In one embodiment, the invention provides an article comprising a substrate and a coating, in particular a decorative coating, said coating comprising an LC/QD of formula (I) as described herein, As described herein, includes oleylamine, oleic acid, and surfactants except trioctylphosphine.

In a sixth aspect, the invention relates to a method of making a polymer composition as described herein. The method comprises steps known in the art except using an ink as described herein as the one or only starting material.

In a seventh aspect, the invention relates to a method of making an intermediate product as described herein. Hereinafter, embodiments of the present invention will be described in more detail.

The intermediate according to the invention may be obtained by solution processing. This is considered a significant advantage as it allows all layers to be produced by simple techniques suitable for large area and continuous operation. Accordingly, the present invention provides a method of making an intermediate product as described herein, the method comprising: (e) providing a substrate; and (f) preferably herein. Depositing a solid polymer composition as described herein onto the substrate by printing an ink as described followed by drying and/or solidifying the coating. ..

In an eighth aspect, the invention relates to a method of making an electronic device as described herein. Hereinafter, embodiments of the present invention will be described in more detail.

The manufacture of devices starting from the above intermediates is known per se, but has not yet been applied to the particular intermediates of the invention.

The following examples are provided to further illustrate the invention. These examples are provided without intending to limit the scope of the invention. Unless otherwise noted, all chemicals were purchased from Aldrich.

Example 1: Synthesis from solid material obtained by precipitation method

Lead cesium tribromide (CsPbBr ₃ ) was synthesized by mixing PbBr ₂ and CsBr under acidic conditions. That is, 2 mmol of PbBr ₂ (0.731 g, 98% ABCR) was dissolved in 3 mL of concentrated HBr (48%, Alpha Acer). 2mmol of CsBr (0.426g, 99.9% ABCR) was dissolved in _{H 2} O in 1 mL, was added to PbBr ₂ solution. A bright orange solid immediately precipitated from the solution. The solid was filtered, washed 4 times with pure EtOH and dried under reduced pressure for 5 hours to give 1.12 g of pure orthorhombic CsPbBr ₃ (yield 96.8%). This material does not show any luminescence. SEM analysis showed that the average particle size was in the range of 0.5-6 microns.

Dry CsPbBr ₃ powder was added to oleylamine (70%, Aldrich) (CsPbBr ₃ :oleylamine=1:10), and toluene (>99.7%, fulca). The final concentration of CsPbBr ₃ was 1%. The mixture was then dispersed by ball milling with yttrium-stabilized zirconia beads having a diameter of 200 microns for 1 hour at ambient conditions to give an ink with green luminescence. A Perkin Elmer Lambda 45 spectrophotometer and a Perkin Elmer LS50B spectrofluorometer equipped with a Hamamatsu R928 phototube were used to record the absorption and luminescence properties of the ink in an air equilibrium solution contained in a 10 mm quartz cuvette, respectively. The ink was diluted with toluene until the absorbance value at the excitation wavelength was below 0.1.

The above ink had a photoluminescence quantum yield of 71% and had an emission peak centered at 507 nm. The FWHM of emission was determined to be 19 nm. A fluorescein (analytical reference grade, Aldrich) solution in 0.1 M NaOH was used as a photoluminescence quantum yield standard.

TEM analysis of the ink (Figure 2) showed the presence of cubic shaped particles with a very narrow particle size distribution.

For XRD analysis of the ink, QD was precipitated with acetonitrile and dried for analysis. Cubic CsPbBr ₃ was the predominant phase.

The above experiment was repeated except that pure methyl methacrylate was used instead of toluene. The final ink showed a slightly blue shifted emission.

Example 2: Synthesis from solid material obtained by flame spray pyrolysis

For the preparation of the CsPbBr ₃ precursor, 2.5 mmol cesium acetate (0.48 g, ABCR), 2.5 mmol lead 2-ethylhexanoate (1.23 g, Strem) were added to 2-ethylhexane (Aldrich. ), and the mixture was dissolved by heating at 150° C. for 1 hour. After cooling to room temperature, 7.5 mmol of bromobenzene (1.18 g, Aldrich) was added to the mixture. The resulting solution was diluted with xylene to a mass of 1:2. The precursor was fed to the spray nozzle (9 mLmin ^-1 , HNP Mikrosysteme, micro annular gear pump mzr-2900), dispersed with oxygen (9 lmin ^-1 , PanGas tech) and premixed methane-oxygen flame (CH ₄ :1. It ignited at ₂ lmin ⁻¹ , O ₂ : 2.2 lmin ⁻¹ ). The off-gas was filtered through a glass fiber filter (Schleicher & Schuell) with a vacuum pump (Busch, Seco SV1040CV) at about 20 m ³ h ^-1 . The resulting oxide powder was collected from a glass fiber filter. XRD analysis of the obtained powder was confirmed to compositions CsPbBr _3. SEM analysis showed an average particle size of less than 500 nm.

CsPbBr ₃ powder was added to Span65 (Aldrich) (CsPbBr ₃ :Span65=1:10) and toluene (>99.7%, fulca). The final concentration of CsPbBr ₃ was 0.2%. The mixture was then dispersed using yttrium-stabilized zirconia beads with a diameter of 50 microns by ball milling for 30 minutes at ambient conditions to give an ink with green luminescence. As shown in Example 1, the absorption and luminescence properties of the ink were recorded. The photoluminescence quantum yield of the above ink was 37% with an emission peak centered at 511 nm. The FWHM of emission was determined to be 25 nm.

For XRD analysis of the ink, QD was precipitated with acetonitrile and dried for analysis. Cubic CsPbBr ₃ was the predominant phase.

Example 3: Synthesis from solid material composed of a mixture of two different precursors

In those equal molar ratios leading to net stoichiometry of CsPbBr _3, commercial CsBr (99.9%, ABCR), and PbBr ₂ (98%, ABCR) were mixed powder. The salt mixture, oleylamine (70%, Aldrich) (CsPbBr _3: oleylamine = 1: 10), and toluene (> 99.7%, Fluka) was added to. The final concentration of CsPbBr ₃ was 0.2%. The mixture was then dispersed with yttrium-stabilized zirconia beads having a diameter of 50 microns by ball milling at ambient conditions for 150 minutes to give an ink with green luminescence. As shown in Example 1, the absorption and luminescence properties of the ink were recorded. The photoluminescence quantum yield of the above ink was 48% with an emission peak centered at 503 nm. The FWHM of emission was determined to be 37 nm.

For XRD analysis of the ink, QD was precipitated with acetonitrile and dried for analysis. Cubic CsPbBr ₃ was the predominant phase.

Example 4: Synthesis from solid material obtained by precipitation method using different dispersion methods

Cesium lead iodobromide (CsPbBr ₂ I) was synthesized by mixing PbBr ₂ and CsI from a methylsulfoxide (DMSO) solution. That is, 1 mmol of PbBr ₂ (0.367 g, 98% ABCR) was dissolved in 2 mL of DMSO (>99.7%, Across). 1 mmol CsI (0.259 g, 99.9%, Alpha Acer) was dissolved in 1 mL DMSO and added to the PbBr ₂ solution. After adding 20 mL of toluene (99.7%, fulca), a bright red solid immediately precipitated from the solution. The solid was filtered, washed 4 times with pure EtOH and dried under reduced pressure for 5 hours to give 0.58 g of pure orthorhombic CsPbBr ₂ I (92.6% yield). This material does not show any luminescence.

0.02 g of the obtained salt was added to 9.78 g of tetradecane (99%, Aldrich), 0.2 g of oleylamine (70%, Aldrich), 10 g of yttrium-stabilized zirconia beads having a diameter of 50 microns, and 3 cm. Into a 30 mL glass vial containing a magnet bar. The mixture was mixed at 1000 rpm at 120°C for 4 hours. After cooling to room temperature, the ink was filtered through a 0.45um PTFE filter and a yellow luminescence was observed. As shown in Example 1, the absorption and luminescence properties of the ink were recorded. Photoluminescence was characterized by an emission peak centered at 552 nm with a FWHM of the emission peak at 30 nm.

All further experiments below were performed by ball milling using similar processing parameters (LC/QD:surfactant ratio = 1:10, milling bead size = 50 microns, milling time = 30 minutes, in ink). LC/QD concentration = 0.2%, filtered through a 0.45 μm PTFE syringe filter for optical characterization, optical characterization is the same as in Example 1).

Example 10: Synthesis from solid material obtained by dry milling method

Lead cesium tribromide (CsPbBr ₃ ) was synthesized by milling PbBr ₂ and CsBr. That is, 2 mmol of PbBr ₂ (0.731 g, 98% ABCR) and 2 mmol of CsBr (0.426 g, 99.9% ABCR) were milled with yttrium-stabilized zirconia beads (diameter 2 mm) for 2 hours to give 1 0.08 g of pure orthorhombic CsPbBr ₃ was obtained (yield 93.3%). This material showed no luminescence. SEM analysis showed that the average particle size was in the range of 0.5-6 microns.

Orange CsPbBr ₃ powder was added to oleylamine (70%, Aldrich) (CsPbBr ₃ :oleylamine=5:1), and toluene (>99.7%, fulca). The final concentration of CsPbBr ₃ was 1%. The mixture was then dispersed by ball milling with yttrium-stabilized zirconia beads having a diameter of 50 microns for 1 hour at ambient conditions to give an ink with green luminescence. As shown in Example 1, the absorption and luminescence properties of the ink were recorded.

The photoluminescence quantum yield of the above ink was 85% with an emission peak centered at 502 nm. The FWHM of the emission was determined to be 19 nm.

The green emitting ink was then mixed with a 10% solution of cyclic olefin copolymer (COC, TOPAS Advanced Polymers) in toluene, coated on a glass substrate and dried at 60°C for 15 minutes. After drying, the resulting optical properties of the film were measured with a spectrofluorometer equipped with an integrating sphere (Quantaurus Absolute PL Quantum Yield Measurement System C1134711, Hamamatsu). The photoluminescence quantum yield of the film was 80% with an emission peak centered at 502 nm. The FWHM was determined to be 19 nm.

Example 11: Adjustment of emission wavelength after synthesis

Solid CsPbBr ₃ material from Example 10, oleylamine (70%, Aldrich) (CsPbBr _3: oleylamine = 2: 1), and n- heptane (99%, Aldrich) was added to. The final concentration of CsPbBr ₃ was 1%. The mixture was then dispersed by ball milling with yttrium-stabilized zirconia beads having a diameter of 50 microns for 1 hour at ambient conditions to give an ink with green luminescence. As shown in Example 1, the absorption and luminescence properties of the ink were recorded. The photoluminescence quantum yield of the above ink was 89% with an emission peak centered at 501 nm. The FWHM of emission was determined to be 20 nm.

Cesium lead triiodide (CsPbI ₃ ) was synthesized by milling PbI ₂ and CsI. That is, 2 mmol of PbI ₂ (0.922 g, 99%, Aldrich) and 2 mmol of CsI (0.519 g, 99%, ABCR) were milled with yttrium-stabilized zirconia beads (diameter 2 mm) for 2 hours to give 1 0.387 g of pure orthorhombic CsPbI ₃ was obtained (yield 96.2%). This material showed no luminescence.

Yellow CsPbI ₃ powder was added to oleylamine (70%, Aldrich) (CsPbBr ₃ :oleylamine=2:1), and n-heptane (99%, Aldrich). The final concentration of CsPbI ₃ was 1%. The mixture was then dispersed by ball milling with yttrium-stabilized zirconia beads having a diameter of 50 microns for 3 hours at ambient conditions to give an ink with red luminescence. The absorption and luminescence properties of the ink were recorded as shown in Example 1, however, a solution of cresyl violet (Aldrich) in MeOH was used as the photoluminescence quantum yield standard. The photoluminescence quantum yield of the above ink was 61% with an emission peak centered at 674 nm. The FWHM of emission was determined to be 48 nm.

Next, 1 mL of green emitting CsPbBr ₃ ink was mixed with 150 μl of red emitting CsPbI ₃ ink. The mixture was found to change emission wavelength immediately, centered at 529 nm, have a photoluminescence quantum yield of 58%, and a FWHM of 21 nm. There was no evidence of photoluminescence from the original CsPbBr ₃ ink (501 nm) and CsPbBrI ₃ ink (676 nm).

In a further test, 0.5 mL of green emitting CsPbBr ₃ ink was mixed with 1 mL of red emitting CsPbI ₃ ink. The mixture was found to change emission wavelength immediately, centered at 640 nm, had a photoluminescent quantum yield of 86%, and a FWHM of 37 nm. Again, no trace of photoluminescence from the original CsPbBr ₃ ink (501 nm) and CsPbBrI ₃ ink (676 nm) was found.

Example 12: Solventless system

0.5 g of the green emitting ink of Example 10 was mixed with 1 g of Permabond UV681 UV-curable adhesive (Permabond Engineering Adhesives). The solvent present in the green emitting ink was removed by heating the mixture at 80° C. for 90 minutes. The remaining material was then coated between two glass slides and UV cured for 30 seconds (UVACUBE 100, Honle UV Technology) to a solid polymer film. The optical properties of the resulting film were measured as in Example 10. The photoluminescence quantum yield of the film was 77% with an emission peak centered at 502 nm. The FWHM was determined to be 19 nm.

Example 13: Composition with styrene block copolymer and solid polymer composition

0.5 g of the green emitting ink from Example 11 (CsPbBr ₃ ink) was mixed with 5 g of 10 wt% polystyrene-block-polyisoprene-block-polystyrene (Aldrich, 14 wt% styrene) in toluene. The material was then coated onto glass slides and cured at 60°C into a solid polymer film. The optical properties of the resulting film were measured as in Example 10. The photoluminescence quantum yield of the film was 84% with an emission peak centered at 501 nm. FWHM was determined to be 20 nm.

0.5g green emitting ink from Example 11 (CsPbBr ₃ inks) of 5g, polystyrene n- heptane 10% - block - poly (ethylene -ran- butadiene) - block - mixed with polystyrene (Aldrich) did. The material was then coated onto glass slides and cured at 60°C into a solid polymer film. The optical properties of the resulting film were measured as in Example 10. The photoluminescence quantum yield of the film was 83% with an emission peak centered at 501 nm. FWHM was determined to be 20 nm. Hereinafter, examples of embodiments of the present invention will be listed.
[1]
A method for producing a light emitting crystal having a diameter of 2 to 50 nm, wherein the light emitting crystal is selected from the compounds of formula (I),
M ¹ _a M ² _b X _c (I)
In the formula:
M ¹ represents one or more alkali metals selected from Cs, Rb, K, Na and Li,
M ² represents one or more metals selected from the group consisting of Ge, Sn, Pb, Sb, and Bi,
X represents one or more halides selected from the group consisting of Cl, Br, and I,
a represents 1 to 4,
b represents 1-2,
c represents 3 to 9;
The method comprises the following steps:
(A) providing a solid material, wherein the solid material has a stoichiometric composition of (i) a mole of M ¹ , b mole of M ² , and c mole of X, and ( ii) having a mean particle size of at least 15 nm and a polydisperse size distribution of typically 15 nm to 100 μm;
(B) Dispersing the material in the presence of a liquid, the liquid comprising: (i) a liquid surfactant, (ii) a combination of a surfactant and a solvent, (iii) a surfactant, a solvent, And a prepolymer or a combination of polymers, and (iv) a combination of a surfactant and a liquid prepolymer, said dispersion being caused by a milling ball which is agitated.
Including the method.
[2]
The dispersion of step (b) is
Produced by agitated milling balls having a ball diameter of 10 to 1000 μm; and/or
Produced by a specific power input of at least 100 W/kg per unit mass of suspension; and/or
A method according to item 1, which occurs at a temperature of less than 120°C.
[3]
Item 3. The method according to Item 1 or 2, wherein the luminescent crystal is selected from the group of Cs ₁ Pb ₁ X ₃ .
[4]
Item 1 wherein the solvent is selected from the group of aliphatic hydrocarbons (including straight chain, branched chain and cyclic hydrocarbons), aromatic hydrocarbons, ethers (including glycol ethers), esters, alcohols, ketones The method according to any one of 3 to 3.
[5]
Item 5. The item according to any one of Items 1 to 4, wherein the surfactant is selected from the group of nonionic surfactants, anionic surfactants, cationic surfactants, and zwitterionic surfactants. the method of.
[6]
Items 1-5, wherein the prepolymer is selected from the group of acrylates, carbonates, sulfones, epoxies, vinyls, urethanes, imides, esters, furans, melamines, styrenes and silicones, especially acrylates, urethanes, styrenes and silicones. The method according to any one of 1.
[7]
In the step (a), the solid material is
Obtained by a dry synthesis process including gas phase reaction and dry milling; or
Obtained by a wet synthesis process; or
7. The method of any one of paragraphs 1-6, which is formed in situ by the stoichiometric reaction of two or more precursors corresponding to the net stoichiometric composition of formula (I).
[8]
The dry synthesis process is a gas phase process, including decomposition and pyrolysis processes, such as flame spray pyrolysis processes;
The wet synthesis process is a precipitation process from a solvent-based phase or an aqueous phase;
Item 8. The in situ formation occurs by ball milling the starting material in the presence of a surfactant and optionally a solvent, and/or a liquid prepolymer, and/or a dissolved solid polymer. Method.
[9]
The mass ratio of solid material: liquid material (solvent+surfactant) is in the range of 0.0001 to 0.5; and/or
The method according to any one of Items 1 to 8, wherein the mass ratio of the surfactant:solid material is in the range of 100 to 0.1.
[10]
Replacing one or more halogen atoms X of the synthesized luminescent crystal with another halogen atom by anion exchange; and/or
A step of combining two or more kinds of luminescent crystals of formula (I)
The method according to any one of Items 1 to 9, further comprising:
[11]
(I) a luminescent crystal of the formula (I) having a diameter of 2 to 5 nm according to item 1 or 3;
(Ii) a surfactant selected from the group of nonionic surfactants, anionic surfactants, cationic surfactants, and zwitterionic surfactants, including oleylamine, oleic acid, and trioctyl. A surfactant, excluding phosphine;
(Iii) any solvent from the group of aliphatic hydrocarbons (including straight chain, branched chain and cyclic hydrocarbons), aromatic hydrocarbons, ethers (including glycol ethers), esters, alcohols, ketones A solvent, preferably selected;
(Iv) with any polymer or prepolymer, preferably selected from the group of acrylates, epoxies, urethanes, styrenes, silicones, and cyclic olefin copolymers.
A composition in the form of a suspension, comprising:
[12]
The light emitting crystal (i): liquid material (ii)+(iii)+(iv) in a mass ratio of 0.0001 to 0.5; and/or
The mass ratio of surfactant (ii): luminescent crystal (i) is in the range of 100 to 0.05; and/or
12. The composition according to item 11, wherein the concentration of the polymer or prepolymer is in the range of 0.1 to 30% by mass of the total composition.
[13]
The surfactant is selected from the group of anionic surfactants, cationic surfactants, nonionic surfactants, and zwitterionic surfactants, and
13. The composition according to item 11 or 12, wherein the surfactant comprises a non-polar end group selected from the group of alkyl or alkyl-ether chains having 4 to 30 carbon atoms.
[14]
Does not include solvent (iii),
LC/QD(i): the mass ratio of the liquid material (prepolymer (iv)+surfactant (ii)) is preferably in the range of 0.0001 to 0.5, any one of Items 11 to 13. The composition according to the item.
[15]
Surfactant (ii) is a liquid surfactant, is free of solvent (iii) and prepolymer (iv),
The surfactant (ii):LC/QD(i) mass ratio is in the range of 100 to 1,
Item 15. The composition according to any one of items 11 to 14.
[16]
(I) a luminescent crystal of the formula (I) having a diameter of 2 to 50 nm according to item 1 or 2;
(Ii) a surfactant selected from the group of nonionic surfactants, anionic surfactants, cationic surfactants, and zwitterionic surfactants, including oleylamine, oleic acid, and trioctyl. A surfactant, excluding phosphine;
(Iii) a curing/solidifying polymer, preferably selected from the group of acrylate polymers, epoxy polymers, urethane polymers, styrene polymers, silicone polymers, and cyclic olefin copolymers.
A solid polymer composition comprising:
[17]
LC/QD: matrix (polymer+surfactant) mass ratio in the range of 0.0001-0.1;
And/or
The mass ratio of surfactant:LC/QD is in the range of 100 to 0.05,
Item 17. The solid polymer composition according to item 16.
[18]
An intermediate product comprising a sheet-like substrate coated with one or more layers, wherein at least one of said layers is a functional layer, said functional layer comprising the composition according to item 16 or 17. Intermediate product.
[19]
19. The intermediate product according to item 18, wherein the functional layer converts blue light into white light.
[20]
An apparatus selected from the group of electronics and optical devices, said apparatus comprising a substrate and a functional layer; said functional layer being an LC/QD of formula (I) according to item 1 or 3, A surfactant according to any one of items 1, 5 or 13 is included,
apparatus.
[21]
21. The device according to item 20, which is a device selected from the group consisting of a display, a mobile device, a light emitting device, and a solar cell, in particular an LCD display or a quantum dot LED (QLED).
[22]
An article comprising a substrate and a coating, in particular a decorative coating, said coating according to item 1 or 3 and the LC/QD of formula (I) and any one of items 1, 5 or 13. An article comprising the described surfactant.
[23]
(A) providing a substrate,
(B) The solid polymer composition according to item 16 or 17 is preferably added to the above-mentioned group by coating or printing the composition according to any one of items 11 to 15 and subsequently drying and/or solidifying the composition. Depositing on wood,
20. A method for producing the intermediate product according to item 18 or 19, which comprises:
[24]
Any of items 11 to 15 for producing an intermediate product according to item 18 or 19, or for producing an apparatus according to item 20 or 21, or for producing an article according to item 22. Use of the composition according to paragraph 1.
[25]
Use of the composition according to item 16 or 17 for converting blue light into white light, especially in light emitting diodes (LEDs) or liquid crystal displays.

Claims (23)

A method for producing a light emitting crystal, wherein the light emitting crystal is selected from compounds of formula (I):
Cs ₁ Pb ₁ X ₃ (I)
In the formula:
X represents one or more halides selected from the group consisting of Cl, Br, and I,
The luminescent crystals have an average diameter of 3 to 15 nm, the diameter distribution indicated by the FWHM value is less than 40 nm of the peak for emission of 480 to 550 nm or 600 to 680 nm, all three orthogonal dimensions. Has an aspect ratio (long axis direction: short axis direction) of 1 to 2;
The method comprises the following steps:
(A) providing a solid material, said solid material having a stoichiometric composition of (i) 1 mole of Cs, 1 mole of Pb, and 3 moles of X , and (ii) Having an average particle size of at least 15 nm;
(B) Dispersing the material in the presence of a liquid, the liquid comprising: (i) a liquid surfactant, (ii) a combination of a surfactant and a solvent, (iii) a surfactant, a solvent, And a prepolymer or a combination of polymers, and (iv) a combination of a surfactant and a liquid prepolymer, the dispersion being caused by a stirred milling ball. The dispersion of step (b) is
Produced by agitated milling balls having a ball diameter of 10-1000 μm; and/or produced by a specific power input of at least 100 W/kg per unit mass of suspension; and/or produced at a temperature below 120° C., The method of claim 1. The solvent is selected from the group of aliphatic hydrocarbons (including straight chain, branched chain, and cyclic hydrocarbons), aromatic hydrocarbons, ethers (including glycol ethers), esters, alcohols, ketones. The method according to 1 or 2. The method according to claim 1 or 2, wherein the surfactant is selected from the group of nonionic surfactants, anionic surfactants, cationic surfactants, and zwitterionic surfactants. The method according to claim 1 or 2, wherein the prepolymer is selected from the group of acrylates, carbonates, sulfones, epoxies, vinyls, urethanes, imides, esters, furans, melamines, styrenes, and silicones. In the step (a), the solid material is
Obtained by a dry synthesis process comprising gas phase reaction and dry milling; or obtained by a wet synthesis process; or a stoichiometric reaction of two or more precursors corresponding to the net stoichiometric composition of formula (I) The method of claim 1 or 2 formed in situ by. The dry synthesis process is a gas phase process including a decomposition process and a thermal decomposition process;
The wet synthesis process is a precipitation process from a solvent-based phase or an aqueous phase;
Forming in said situ, and the surfactant, the presence of any solvent, and / or liquid prepolymers and / or dissolved solids polymer occurs by ball milling the starting materials, in claim 6 The method described. The mass ratio of the solid material: the liquid material (solvent+surfactant) is in the range of 0.0001 to 0.5; and/or the mass ratio of the surfactant: the solid material is 100 to 0.1. The method according to claim 1 or 2, which is in the range. Replacing one or more halogen atoms X of the synthesized luminescent crystal with another halogen atom by anion exchange; and/or combining two or more types of luminescent crystals of formula (I), The method according to Item 1 or 2. (I) a luminescent crystal;
(Ii) a surfactant selected from the group of nonionic surfactants, anionic surfactants, cationic surfactants, and zwitterionic surfactants, including oleylamine, oleic acid, and trioctyl. A surfactant, excluding phosphine;
(Iii) any solvent;
(Iv) including any polymer or prepolymer,
The luminescent crystal is selected from compounds of formula (I),
Cs ₁ Pb ₁ X ₃ (I)
In the formula:
X represents one or more halides selected from the group consisting of Cl, Br, and I,
The luminescent crystals have an average diameter of 3 to 15 nm, the diameter distribution indicated by the FWHM value is less than 40 nm of the peak for emission of 480 to 550 nm or 600 to 680 nm, all three orthogonal dimensions. The composition in the form of a suspension, wherein the aspect ratio (long axis direction: short axis direction) of is 1-2. The mass ratio of the luminescent crystal (i): liquid material (ii)+(iii)+(iv) is in the range of 0.0001 to 0.5; and/or the surfactant (ii): the luminescent crystal. the weight ratio of (i) is in the range of from 100 to 0.05; and / or polymer or prepolymer concentration is in the range of 0.1 to 30% by weight of the total composition, according to claim 10 Composition. The surfactant is selected from the group of anionic surfactants, cationic surfactants, nonionic surfactants, and zwitterionic surfactants, and the surfactant is from 4 to 30 carbons. The composition according to claim 10 , comprising a non-polar end group selected from the group of alkyl or alkyl-ether chains having atoms. The solvent (iii) is not contained, and/or the mass ratio of the luminescent crystals (i): liquid material (prepolymer (iv)+surfactant (ii)) is in the range of 0.0001 to 0.5, The composition according to claim 10 . The surfactant (ii) is a liquid surfactant, does not include the solvent (iii) and the prepolymer (iv),
The mass ratio of the surfactant (ii): the light emitting crystal (i) is in the range of 100 to 1,
The composition according to claim 10 . (I) a luminescent crystal;
(Ii) a surfactant selected from the group of nonionic surfactants, anionic surfactants, cationic surfactants, and zwitterionic surfactants, including oleylamine, oleic acid, and trioctyl. A surfactant, excluding phosphine;
(Iii) including a curing/solidifying polymer,
The luminescent crystal is selected from compounds of formula (I),
Cs ₁ Pb ₁ X ₃ (I)
In the formula:
X represents one or more halides selected from the group consisting of Cl, Br, and I,
The luminescent crystals have an average diameter of 3 to 15 nm, the diameter distribution indicated by the FWHM value is less than 40 nm of the peak for emission of 480 to 550 nm or 600 to 680 nm, all three orthogonal dimensions. The solid polymer composition has an aspect ratio (long axis direction: short axis direction) of 1 to 2. The mass ratio of the luminescent crystal:matrix (polymer+surfactant) is in the range of 0.0001 to 0.1;
And/or the mass ratio of the surfactant to the luminescent crystal is in the range of 100 to 0.05,
The solid polymer composition according to claim 15 . An article comprising a sheet-like substrate coated with one or more layers, wherein at least one of said layers is a functional layer, said functional layer comprising the composition of claim 15. .. The article of claim 17 , wherein the functional layer converts blue light to white light. A device selected from the group of electronics and optical devices, said device comprising a substrate and a functional layer; said functional layer comprising a luminescent crystal and a surfactant,
The luminescent crystal is selected from compounds of formula (I),
Cs ₁ Pb ₁ X ₃ (I)
In the formula:
X represents one or more halides selected from the group consisting of Cl, Br, and I,
The luminescent crystals have an average diameter of 3 to 15 nm, the diameter distribution indicated by the FWHM value is less than 40 nm of the peak for emission of 480 to 550 nm or 600 to 680 nm, all three orthogonal dimensions. The aspect ratio (major axis direction: minor axis direction) of the device is 1 to 2. 20. The device of claim 19 , selected from the group consisting of a display, a mobile device, a light emitting device, and a solar cell. An article comprising a substrate and a coating, the coating comprising a luminescent crystal and a surfactant,
The luminescent crystal is selected from compounds of formula (I),
Cs ₁ Pb ₁ X ₃ (I)
In the formula:
X represents one or more halides selected from the group consisting of Cl, Br, and I,
The luminescent crystals have an average diameter of 3 to 15 nm, the diameter distribution indicated by the FWHM value is less than 40 nm of the peak for emission of 480 to 550 nm or 600 to 680 nm, all three orthogonal dimensions. The aspect ratio (major axis direction: minor axis direction) of the article is 1-2. (A) providing a substrate,
(B) depositing the solid polymer composition of claim 15 on the substrate by coating or printing the composition of claim 10 followed by drying and/or solidifying;
18. A method of making an article according to claim 17 , comprising: 20. The device of claim 19 , selected from the group consisting of an LCD display and a quantum dot LED.